Researchers at the University of California, Riverside have developed a new gel that delivers oxygen to chronic wounds, potentially reducing the risk of amputations for patients who do not heal with conventional treatments.
Chronic wounds are defined as injuries that fail to heal within a month. These wounds affect approximately 12 million people globally each year, including about 4.5 million in the United States. Among those affected in the U.S., one in five may eventually require an amputation.
The research team led by Iman Noshadi, associate professor of bioengineering at UC Riverside, designed the gel to address a primary cause of chronic wound persistence: lack of oxygen deep within damaged tissue. Without adequate oxygen supply, wounds remain inflamed and vulnerable to infection.
“Chronic wounds don’t heal by themselves,” said Noshadi. “There are four stages to healing chronic wounds: inflammation, vascularization where tissue starts making blood vessels, remodeling, and regeneration or healing. In any of these stages, lack of a stable, consistent oxygen supply is a big problem.”
When insufficient oxygen reaches injured areas—a condition known as hypoxia—healing is disrupted. The researchers described their approach in Nature Communications Materials.
The gel contains water and a choline-based liquid that is antibacterial and biocompatible. When used with a small battery similar to those found in hearing aids, it splits water molecules electrochemically to produce continuous oxygen delivery directly into wound sites.
Unlike surface-only treatments, this gel molds itself precisely to each wound’s contours before setting. This allows it to fill crevices where infection risk is highest and ensures steady oxygen delivery for up to a month—addressing the need for sustained treatment during the lengthy vascularization phase.
Tests on diabetic and older mice showed untreated wounds often failed to heal and were fatal; however, animals treated with weekly applications of the patch healed in about 23 days and survived.
“We could make this patch as a product where the gel may need to be renewed periodically,” said Prince David Okoro, doctoral candidate at UC Riverside and co-author of the study.
In addition to providing stable oxygen levels, choline in the gel helps modulate immune response and reduce excessive inflammation common in chronic wounds.
“There are bandages that absorb fluid, and some that release antimicrobial agents,” Okoro said. “But none of them really address hypoxia, which is the fundamental problem. We’re tackling that directly.”
The technology may also have future applications beyond wound care since delivering sufficient oxygen remains challenging when growing replacement tissues or organs—a focus area for Noshadi’s laboratory.
“When the thickness of a tissue increases, it’s hard to diffuse that tissue with what it needs so cells start dying,” Noshadi said. “This project can be seen as a bridge to creating and sustaining larger organs for people in need of them.”
Baishali Kanjilal, bioengineer at UC Riverside and co-author on the paper, pointed out other contributing factors behind chronic wound prevalence such as sedentary lifestyles leading to reduced immune responses alongside aging populations and rising diabetes rates.
“Our sedentary lifestyles are causing our immune responses to decrease,” she said. “It’s hard to get to societal roots of our problems. But this innovation represents a chance to reduce amputations, improve quality of life, and give the body what it needs to heal itself.”
